Effect of surfactants on carbon monoxide fermentations byButyribacterium methylotrophicum

Butyribacterium methylotrophicum has been grown on carbon monoxide as its carbon and energy source in the presence of various surfactants that are capable of forming microbubble dispersions for the screening of surfactants for use in microbubble-sparged synthesis gas fermentations. In the range of 0–3 times the critical micelle concentration, the presence of Tween surfactants was not significantly inhibitory to growth, final cell density, and fermentation stoichiometry, although some of the Brij surfactants caused significant inhibition. As the batch fermentations entered the stationary phase both the pH and the ratio of acetate to butyrate decreased.